arch/x86/lib/zimage.c

   1 /*
   2  * Copyright (c) 2011 The Chromium OS Authors.
   3  * (C) Copyright 2002
   4  * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation; either version 2 of
  12  * the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  */
  24
  25 /*
  26  * Linux x86 zImage and bzImage loading
  27  *
  28  * based on the procdure described in
  29  * linux/Documentation/i386/boot.txt
  30  */
  31
  32 #include <common.h>
  33 #include <asm/io.h>
  34 #include <asm/ptrace.h>
  35 #include <asm/zimage.h>
  36 #include <asm/realmode.h>
  37 #include <asm/byteorder.h>
  38 #include <asm/bootparam.h>
  39
  40 /*
  41  * Memory lay-out:
  42  *
  43  * relative to setup_base (which is 0x90000 currently)
  44  *
  45  *      0x0000-0x7FFF   Real mode kernel
  46  *      0x8000-0x8FFF   Stack and heap
  47  *      0x9000-0x90FF   Kernel command line
  48  */
  49 #define DEFAULT_SETUP_BASE      0x90000
  50 #define COMMAND_LINE_OFFSET     0x9000
  51 #define HEAP_END_OFFSET         0x8e00
  52
  53 #define COMMAND_LINE_SIZE       2048
  54
  55 unsigned generic_install_e820_map(unsigned max_entries,
  56                                   struct e820entry *entries)
  57 {
  58         return 0;
  59 }
  60
  61 unsigned install_e820_map(unsigned max_entries,
  62                           struct e820entry *entries)
  63         __attribute__((weak, alias("generic_install_e820_map")));
  64
  65 static void build_command_line(char *command_line, int auto_boot)
  66 {
  67         char *env_command_line;
  68
  69         command_line[0] = '\0';
  70
  71         env_command_line =  getenv("bootargs");
  72
  73         /* set console= argument if we use a serial console */
  74         if (!strstr(env_command_line, "console=")) {
  75                 if (!strcmp(getenv("stdout"), "serial")) {
  76
  77                         /* We seem to use serial console */
  78                         sprintf(command_line, "console=ttyS0,%s ",
  79                                 getenv("baudrate"));
  80                 }
  81         }
  82
  83         if (auto_boot)
  84                 strcat(command_line, "auto ");
  85
  86         if (env_command_line)
  87                 strcat(command_line, env_command_line);
  88
  89         printf("Kernel command line: \"%s\"\n", command_line);
  90 }
  91
  92 void *load_zimage(char *image, unsigned long kernel_size,
  93                   unsigned long initrd_addr, unsigned long initrd_size,
  94                   int auto_boot, void **load_address)
  95 {
  96         struct boot_params *setup_base;
  97         int setup_size;
  98         int bootproto;
  99         int big_image;
 100
 101         struct boot_params *params = (struct boot_params *)image;
 102         struct setup_header *hdr = &params->hdr;
 103
 104         /* base address for real-mode segment */
 105         setup_base = (struct boot_params *)DEFAULT_SETUP_BASE;
 106
 107         if (KERNEL_MAGIC != hdr->boot_flag) {
 108                 printf("Error: Invalid Boot Flag "
 109                         "(found 0x%04x, expected 0x%04x)\n",
 110                         hdr->boot_flag, KERNEL_MAGIC);
 111                 return 0;
 112         } else {
 113                 printf("Valid Boot Flag\n");
 114         }
 115
 116         /* determine boot protocol version */
 117         if (KERNEL_V2_MAGIC == hdr->header) {
 118                 printf("Magic signature found\n");
 119
 120                 bootproto = hdr->version;
 121         } else {
 122                 /* Very old kernel */
 123                 printf("Magic signature not found\n");
 124                 bootproto = 0x0100;
 125         }
 126
 127         /* determine size of setup */
 128         if (0 == hdr->setup_sects) {
 129                 printf("Setup Sectors = 0 (defaulting to 4)\n");
 130                 setup_size = 5 * 512;
 131         } else {
 132                 setup_size = (hdr->setup_sects + 1) * 512;
 133         }
 134
 135         printf("Setup Size = 0x%8.8lx\n", (ulong)setup_size);
 136
 137         if (setup_size > SETUP_MAX_SIZE)
 138                 printf("Error: Setup is too large (%d bytes)\n", setup_size);
 139
 140         /* Determine image type */
 141         big_image = (bootproto >= 0x0200) &&
 142                     (hdr->loadflags & BIG_KERNEL_FLAG);
 143
 144         /* Determine load address */
 145         if (big_image)
 146                 *load_address = (void *)BZIMAGE_LOAD_ADDR;
 147         else
 148                 *load_address = (void *)ZIMAGE_LOAD_ADDR;
 149
 150 #if defined CONFIG_ZBOOT_32
 151         printf("Building boot_params at 0x%8.8lx\n", (ulong)setup_base);
 152         memset(setup_base, 0, sizeof(*setup_base));
 153         setup_base->hdr = params->hdr;
 154
 155         setup_base->e820_entries = install_e820_map(
 156                 ARRAY_SIZE(setup_base->e820_map), setup_base->e820_map);
 157 #else
 158         /* load setup */
 159         printf("Moving Real-Mode Code to 0x%8.8lx (%d bytes)\n",
 160                (ulong)setup_base, setup_size);
 161         memmove(setup_base, image, setup_size);
 162 #endif
 163
 164         printf("Using boot protocol version %x.%02x\n",
 165                (bootproto & 0xff00) >> 8, bootproto & 0xff);
 166
 167         if (bootproto == 0x0100) {
 168                 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
 169                 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
 170
 171                 /*
 172                  * A very old kernel MUST have its real-mode code
 173                  * loaded at 0x90000
 174                  */
 175                 if ((u32)setup_base != 0x90000) {
 176                         /* Copy the real-mode kernel */
 177                         memmove((void *)0x90000, setup_base, setup_size);
 178
 179                         /* Copy the command line */
 180                         memmove((void *)0x99000,
 181                                 (u8 *)setup_base + COMMAND_LINE_OFFSET,
 182                                 COMMAND_LINE_SIZE);
 183
 184                          /* Relocated */
 185                         setup_base = (struct boot_params *)0x90000;
 186                 }
 187
 188                 /* It is recommended to clear memory up to the 32K mark */
 189                 memset((u8 *)0x90000 + setup_size, 0,
 190                        SETUP_MAX_SIZE - setup_size);
 191         }
 192
 193         /* We are now setting up the real-mode version of the header */
 194         hdr = &setup_base->hdr;
 195
 196         if (bootproto >= 0x0200) {
 197                 hdr->type_of_loader = 8;
 198
 199                 if (hdr->setup_sects >= 15) {
 200                         printf("Linux kernel version %s\n",
 201                                (char *)params +
 202                                hdr->kernel_version + 0x200);
 203                 } else {
 204                         printf("Setup Sectors < 15 - "
 205                                "Cannot print kernel version.\n");
 206                 }
 207
 208                 if (initrd_addr) {
 209                         printf("Initial RAM disk at linear address "
 210                                "0x%08lx, size %ld bytes\n",
 211                                initrd_addr, initrd_size);
 212
 213                         hdr->ramdisk_image = initrd_addr;
 214                         hdr->ramdisk_size = initrd_size;
 215                 }
 216         }
 217
 218         if (bootproto >= 0x0201) {
 219                 hdr->heap_end_ptr = HEAP_END_OFFSET;
 220                 hdr->loadflags |= HEAP_FLAG;
 221         }
 222
 223         if (bootproto >= 0x0202) {
 224                 hdr->cmd_line_ptr =
 225                         (uintptr_t)setup_base + COMMAND_LINE_OFFSET;
 226         } else if (bootproto >= 0x0200) {
 227                 setup_base->screen_info.cl_magic = COMMAND_LINE_MAGIC;
 228                 setup_base->screen_info.cl_offset = COMMAND_LINE_OFFSET;
 229
 230                 hdr->setup_move_size = 0x9100;
 231         }
 232
 233         if (bootproto >= 0x0204)
 234                 kernel_size = hdr->syssize * 16;
 235         else
 236                 kernel_size -= setup_size;
 237
 238
 239         if (big_image) {
 240                 if ((kernel_size) > BZIMAGE_MAX_SIZE) {
 241                         printf("Error: bzImage kernel too big! "
 242                                 "(size: %ld, max: %d)\n",
 243                                 kernel_size, BZIMAGE_MAX_SIZE);
 244                         return 0;
 245                 }
 246         } else if ((kernel_size) > ZIMAGE_MAX_SIZE) {
 247                 printf("Error: zImage kernel too big! (size: %ld, max: %d)\n",
 248                        kernel_size, ZIMAGE_MAX_SIZE);
 249                 return 0;
 250         }
 251
 252         /* build command line at COMMAND_LINE_OFFSET */
 253         build_command_line((char *)setup_base + COMMAND_LINE_OFFSET, auto_boot);
 254
 255         printf("Loading %czImage at address 0x%08x (%ld bytes)\n",
 256                big_image ? 'b' : ' ', (u32)*load_address, kernel_size);
 257
 258         memmove(*load_address, image + setup_size, kernel_size);
 259
 260         /* ready for booting */
 261         return setup_base;
 262 }
 263
 264 void boot_zimage(void *setup_base, void *load_address)
 265 {
 266         printf("\nStarting kernel ...\n\n");
 267
 268 #if defined CONFIG_ZBOOT_32
 269         /*
 270          * Set %ebx, %ebp, and %edi to 0, %esi to point to the boot_params
 271          * structure, and then jump to the kernel. We assume that %cs is
 272          * 0x10, 4GB flat, and read/execute, and the data segments are 0x18,
 273          * 4GB flat, and read/write. U-boot is setting them up that way for
 274          * itself in arch/i386/cpu/cpu.c.
 275          */
 276         __asm__ __volatile__ (
 277         "movl $0, %%ebp         \n"
 278         "cli                    \n"
 279         "jmp %[kernel_entry]    \n"
 280         :: [kernel_entry]"a"(load_address),
 281            [boot_params] "S"(setup_base),
 282            "b"(0), "D"(0)
 283         :  "%ebp"
 284         );
 285 #else
 286         struct pt_regs regs;
 287
 288         memset(&regs, 0, sizeof(struct pt_regs));
 289         regs.xds = (u32)setup_base >> 4;
 290         regs.xes = regs.xds;
 291         regs.xss = regs.xds;
 292         regs.esp = 0x9000;
 293         regs.eflags = 0;
 294         enter_realmode(((u32)setup_base + SETUP_START_OFFSET) >> 4, 0,
 295                        &regs, &regs);
 296 #endif
 297 }
 298
 299 int do_zboot(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
 300 {
 301         void *base_ptr;
 302         void *bzImage_addr = NULL;
 303         void *load_address;
 304         char *s;
 305         ulong bzImage_size = 0;
 306
 307         disable_interrupts();
 308
 309         /* Setup board for maximum PC/AT Compatibility */
 310         setup_pcat_compatibility();
 311
 312         if (argc >= 2) {
 313                 /* argv[1] holds the address of the bzImage */
 314                 s = argv[1];
 315         } else {
 316                 s = getenv("fileaddr");
 317         }
 318
 319         if (s)
 320                 bzImage_addr = (void *)simple_strtoul(s, NULL, 16);
 321
 322         if (argc >= 3)
 323                 /* argv[2] holds the size of the bzImage */
 324                 bzImage_size = simple_strtoul(argv[2], NULL, 16);
 325
 326         /* Lets look for */
 327         base_ptr = load_zimage(bzImage_addr, bzImage_size, 0, 0, 0,
 328                 &load_address);
 329
 330         if (!base_ptr) {
 331                 printf("## Kernel loading failed ...\n");
 332         } else {
 333                 printf("## Transferring control to Linux "
 334                        "(at address %08x) ...\n",
 335                        (u32)base_ptr);
 336
 337                 /* we assume that the kernel is in place */
 338                 boot_zimage(base_ptr, load_address);
 339                 /* does not return */
 340         }
 341
 342         return -1;
 343 }
 344
 345 U_BOOT_CMD(
 346         zboot, 2, 0,    do_zboot,
 347         "Boot bzImage",
 348         ""
 349 );